Single-coil linear motors

ABSTRACT

One element comprises a long bar of copper or aluminum transversely pierced at regular intervals by iron cores. The second element- either element may move- comprises a solenoid with an iron core terminating in two long arms, parallel to each other and spaced a little wider than the aforementioned conductive bar, which is positioned by idler wheels between and in line with the arms of the solenoid&#39;&#39;s core. When the solenoid is energized by AC, a repulsion current is induced in the conductive bar and it moves away from the coil, guided by the idler wheels.

52 1 U 1 1.5 S R P15 8502 QR 5 735 162 u tilted States Patent 1 1 1 13,735,162 Alth [451 May 22, 1973 [54] SINGLE-COIL LINEAR MOTORS FOREIGNPATENTS OR APPLICATIONS [76] Inventor; Max A111 6 Tamarack Road, Port989,169 4/1965 Great Britain ..3l0/27 Chester, 453,256 9/1936 GreatBritain ..310 27 [22] Filed: 1972 Primary Examiner-D. F. Duggan [21]App]. No.: 229,267

[57] ABSTRACT 52 us. c1 ..310/13, 310/27 One element comprises a longbar of copper or 51 Int. Cl. ..II02k 41/02 minum transversely Pierced atregular intervals y iron 58 Field of Search ..310/12-19, 27; 318/121,135 eores- The Second elementeither element y movecomprises a solenoidwith an iron core ter- [56] References Cited minating in two long arms,parallel to each other and spaced a little wider than the aforementionedconduc- UNITED STATES PATENTS tive bar, which is positioned by idlerwheels between 2 104 131 1/1938 Matthews 310/13 UX and in line with thearms of the solenoids core. 21365 532 12 1944 Fisher When the solenoidis energized by AC, 21 repulsion current is induced in the conductivebar and it moves away from the coil, guided by the idler wheels.

10 Claims, 4 Drawing Figures SINGLE-COIL LINEAR MOTORS BACKGROUND TOPRESENT DISCLOSURE The present disclosure is a continuation of work inelectric motors that so far has resulted in US. Pat. No. 3 586 976, Mar.2, I971, Eddy Current Brake, and claims granted for Self-Start SinglePhase Motor, Ser. No. I 381. Patent number not assigned as yet.

Concurrent with this application a second application disclosing animproved version of the self-start, single phase motor is beingsubmitted to the Commissioner of Patents.

FIG. 1 is a side view of the motor.

FIG. 2 is a plan view of the same motor.

FIG. 3 illustrates twoversions of the same motor used for vehicletransport.

FIG. 4 schematically illustrates the present invention utilized forrailed transport.

PRINCIPLE OF OPERATION It is well known that a moving field produces acounteracting magnetic field around any conductor it traverses. Whatappears not to be known is that the field originates within the coil andthe flux will follow the path of least magnetic resistance until itsend. Further; it is well known that a moving field generates a currentin what ever conductor it traverses and the magnetic field associatedwith the counter-current is repulsive in respect to the originatingfield. What is not as well known or known at all, is that generatedcountercurrent persists well after the original field has reached itspeak and begins to decay. Thus a conductive slab or plate placed withinan AC field is repulsed by the field.

By utilizing a solenoid with an iron core terminating in long armsparallel to one another, and following a line pointing away from thecoil, we have with the flow of AC current through the coil, a guidedflux field that will repulse and move any conductive material placedwithin the air gap, i.e., the space between the poles.

ADVANTAGES OF PRESENT INVENTION The present invention provides a verysimple, low cost, single-phase linear motor.

Its simplicity and low cost make it suitable for any linerar poweroperation where AC is available.

Motor size can be directly scaled to any power need; small and largeincluding vehicle transport.

Used to power a rail vehicle, its'advantage lies in the simplicity ofthe rails. An aluminum strap pierced by soft iron cores serves as onerail.

Another advantage is that the major portion of the thrust vector islinear, with a smaller vector offset by some 90 from the thrust vector.Air gap is not critical.

The present linear motor has no shading coils, no split-phase winding,no phase-delay capacitor. It has but a single coil.

Multi-phase operation may be achived by utilizing more than one coil onthe motor or by using several motors, each connected to a phase of theinput power.

FIG. 1 illustrates the basic form of the invention. 2, in this design,is the moving segment or armature of the motor. It may be copper oraluminum. 3 is an iron core piercing the moving segment or armature. 5is the solenoid coil and 4 are the solenoid arms or poles. 6 and 7 areidler wheels.

FIG. 2 is a plan view of the same motor; the same digits are used todesignate the parts. 5 is the coil, 4 is the core terminating in theoff-set pole arms, 2 is the conductive armature, 3 the transverse ironcores. 7 is an idler wheel, the others are not shown. B and A illustratethe effective force vecters.

FIG. 3 shows the motor as it may be used for railed transport. 10represents the rail car; 11 is one motor coil which energizes pole arml2; 13 is the coil of the second motor, 14 its pole arms; 15 is theconductive armature supported above ground by stantions 17, while 16 isa traverse iron core. C and D illustrate the effective force vectors.

The use of two linear motors as shown in FIG. 3 permits the vehicle tobe raised above the rails to any predetermined distance, to some extentirrespective of load, then forward motion is secured by energizing thesecond motor, coil and pole 11 and 12 respectively.

FIG. 4 illustrates how two rails and associate linerar motors might beused to support a car. 20 is the car, 21 is one motor, 22 is the railand 23 represents the road bed.

It should be noted that pole arms, 4 in FIG. 1 and 2; 12 in FIG. 3, areconsiderably longer than the cross section of their respective solenoidcores, and that the air gap between the armature and pole arms isrelatively small.

Solenoid cores and pole arms are shown as of laminated magneticallypermeable material; this is most efficient, but cost iron. can also beused. The armature need not be pieced by iron cores, but may be solidcopper or aluminum.

Having described my invention and its manner of manufacture, this iswhat I claim as new and novel and desire to secure by Letters Patent:

1. A single-phase linear motor comprising an electrically conductivemeans generally bar shaped, a solenoid having a magnetically permeablecore terminating in two long, parallel arms spaced a little wider thansaid conductive means, said arms off-set in relation to said solenoid;said conductive means positioned by low friction means permitting saidconductive means to move freely in a line with said parallel arms; whensaid solenoid is energized with AC current, each half cycle produces amagnetic flux originating at the coil and travelling outwards to theends of said pole arms, inducing a counter current in sad conductivemeans and thus driving said conductive means in a direction away fromsaid solenoid.

2. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a solid bar of conductive metal generally rectangular incross section.

3. A device as claimed in claim 1 wherein said electrically conductivemeans is transversely pierced by a plurality of magnetically permeablecores.

4. A device as claimed in claim 1, wherein said permeable magnetic coreand associate arms comprise a solid bar of cast iron.

5. A device as claimed in claim 1, wherein said magnetically permeablecore and associate arms comprise laminated magnetically permeablematerial.

6. A device as claimed in claim I, wherein said parallel arms may be ofa length other than long.

7. A device as claimed in claim 1, wherein said parallel arms may bestraight and without offset.

ductive means is fixed and said solenoid is free to move.

10. A device as claimed in claim 1, wherein said solenoid is fixed andsaid conductive means is free to move.

2. A device as claimed in claim 1 wherein said electrically conductivemeans comprises a solid bar of conductive metal generally rectangular incross section.
 3. A device as claimed in claim 1 wherein saidelectrically conductive means is transversely pierced by a plurality ofmagnetically permeable cores.
 4. A device as claimed in claim 1, whereinsaid permeable magnetic core and associate arms comprise a solid bar ofcast iron.
 5. A device as claimed in claim 1, wherein said magneticallypermeable core and associate arms comprise laminated magneticallypermeable material.
 6. A device as claimed in claim 1, wherein saidparallel arms may be of a length other than long.
 7. A device as claimedin claim 1, wherein said parallel arms may be straight and withoutoffset.
 8. A device as claimed in claim 1, wherein two and moresingle-phase linear motors may be grouped to produce lift and drive asdesired.
 9. A device as claimed in claim 1, wherein said conductivemeans is fixed and said solenoid is free to move.
 10. A device asclaimed in claim 1, wherein said solenoid is fixed and said conductivemeans is free to move.